Apparatus and method for feeding blanks

ABSTRACT

The lateral edges of a continuous web of paper are folded into superimposed relationship and glued together to form a continuous tube. The tube is cut into sack blanks which are fed by a first conveyor belt to a delivery station comprising a pair of nip rolls and a platen mounted to reciprocate transversely relative to the first conveyor belt. The platen has an opening formed therethrough for permitting each sack blank to fall onto a second conveyor for subsequent formation of an end closure on each sack blank.

United States Patent [191 [111 3,759,508 Jepp sson Sept, W, W73

54] APPARATUS Ann Mari-ion iron riannrna 2,665,633 1/1954 Schubert271/010. 4

BLANKS 2,612,982 l0/l952 Michaux l98/24 Inventor: Sven Torsten.Ieppsson,

Drottninggatan 49, Orebro, Sweden Filed: Dec. 6, 1971 Appl. No.: 205,212

Foreign Application Priority Data Dec. 14, 1970 Sweden l69ll/7O U.S. CI.271/69 Int. CI lllllfifilm ZWtW Field of Search 271/63 R, 69, DIG. 4,

References Cited UNITED STATES PATENTS l2/l94l Carlson 27l/DIG. 4

Primary Examiner-Edward A. Srolta Att0rney-Paul S Lempio [57] ABSTRACTThe lateral edges of a continuous web of paper are folded intosuperimposed relationship and glued together to form a continuous tube.The tube is cut into sack blanks which are fed by a first conveyor beltto a delivery station comprising a pair of nip rolls and a platenmounted to reciprocate transversely relative to the first conveyor belt.The platen has an opening formed therethrough for permitting each eachblank to fall onto a second conveyor for subsequent formation of an endclosure on each sack blank.

18 Claims, 3 Drawing Figures PATENTED SE?! 8 I973 SHEET 2 OF 3 PATENTEUSE?! a ma SHEET 3 or 3 APPARATUS AND METHOD FUR l llBlElD'liltlG BLANKSBACKGROUND OF THE INVENTION The invention relates to an apparatus andmethod for forming tubular receptacles, such as paper sacks.

Paper sacks are normally conveyed through a tube forming station whereina continuous web of paper is folded longitudinally and glued together atsuperimposed edges thereof to form a continuous tube. The tube is thencut into suitable lengths to form individual sack blanks. The blanks aremoved through an end closure forming station wherein a strip of paper isfolded and glued over an open end of each sack blank, after which theformed end closure is reinforced with a sewn seam. Alternatively, thebottom closure can be sewn prior to the gluing of a strip ofreinforcement paper thereover.

The conveyance of the sack blanks from the tube forming station to theend closure forming station requires a 90 change in the direction offeed for the sack blanks. Such an abrupt change gives rise to numerousfeeding problems which, to date, have normally been solved by the manualtransfer of stacked sack blanks to the latter station. The primaryreason for utilizing such manual feeding methods has been the difficultyof perfecting a feeding device and method for reliably gripping andfeeding only one sack at a time, while yet maintaining highmanufacturing speeds.

Attempts to engage an edge of an individual sack blank for feedingpurposes have oftentimes failed since the tendency is to inadvertentlyengage and sew several blanks together simultaneously. This problem isespe cially apparent with respect to expandable sack blanks which arefolded inwardly along their side edges. Another possible solution to theproblem is to employ suction cups or the like to grip a sack blank fromabove and lift it off its stack. However, this solution has also provedimpracticable since the tubular sack blank has a tendency to open, thuspreventing its precise feed to the end closure forming station.

SUMMARY OF THE INVENTEON An object of the present invention is toovercome the above, briefly described problems by providing an apparatusand method for economically and efficiently feeding blanks, such aspaper sack blanks. Such apparatus is particularly useful in sack or bagforming machines wherein a continuous web is formed into a tube, cutinto separate blanks and an open end of each blank is thereafter closed.The apparatus of this invention essentially comprises a delivery stationhaving a platen reciprocally mounted therein to receive blanks from afirst conveyor in one direction and for precisely and expeditiouslyplacing each blank onto a second conveyor to move the blank in a second,transverse direction.

BRIEF DESCRllPTlON OF THE DRAWHNGS Other objects of this invention willbecome apparent from the following description and accompanying drawingswherein:

FIG. 1 is a top plan view schematically illustrating a paper sackforming machine embodying this invention;

FIG. 2 is a perspective view of a delivery station employed in suchmachine; and

FIG. 3 is a perspective view of a reciprocal platen employed in thedelivery station.

DETAILED DESCRIPTION FIG. 1 schematically illustrates a tube formingmeans or station l and an end closure forming means or station 2,adapted for the manufacture of paper sacks or the like. The paper sacksare formed by longitudinally folding and gluing together one or moreplies of paper originating at rolls 3. After the continuous web of paperhas been folded and glued together to form a continuous tube, the tubeis cut into separated, tubular sack blanks.

The sack blanks, or any other types of deliverable articles, are fedfrom the tube forming station to a delivery means or station 6 by afirst endless conveyor means or belt 4 which moves in a first lineardirection theretoward. The delivery station delivers the sack blanks toa second endless conveyor means or belt 7, positioned vertically belowbelt 41 to move in a second direction preferably perpendicular to thefirst direction, which carries the blanks to the end closure formingstation.

The latter station comprises a conventional combined sewing and gluingmachine wherein a strip of paper is folded and glued over one open endof each sack blank. The formed end closure may be reinforced by means ofa sewn seam, formed along the attached strip of paper. The completedsacks are then fed out onto an intermittently operating third conveyorbelt 8 on which the sacks are laid in stacks 9.

Delivery station 6 is clearly shown in FIG. 2. When the sack blanksarrive at the delivery station, along the first linear path on conveyorbelt 4, each blank is moved between two feed or nip roll means lid. Therolls rotate at a sufficiently high speed to discharge and impel eachsack blank so that the leading end thereof fully reaches the rearwardend of the delivery station. F ragments'of a vertically disposed andhorizontally adjustable baffle plate 16b are shown. in lFlG. 2. Suchbaffle plate may be adjusted to accommodate blanks of various widths toprecisely guide and locate each blank over the platen.

Upon entry into the delivery station, the sack blank is urged downwardlyby overlying guide means or rails il7, converging downwardly toward aplaten ill from rolls l0, and thereafter falls by gravity onto theplaten. As the stationary guide-rails force the tubular sack blankdownwardly, they simultaneously prevent the blank from opening under theinfluence of the encountered air resistance. This function is veryadvantageous since it allows the delivery station to operate at highdelivery speeds. i

An extensible and retractable fluid actuator, such as a double-actinghydraulic cylinder having it housing secured to a stationary frame ofthe delivery station, is operatively connected to platen lit by theillustrated bellcrank and lost-motion mechanism. Thus, reciprocation ofthe cylinder rod will in turn reciprocate the platen in a seconddirection, perpendicular to the direction of feed of the sack blanksinto the delivery station. Platen 11 is carried on rollers 31 which runin guide-rails l5 and is guided laterally by thrust rollers M thereception ofa blank therein. During the blank feeding operation, eachsack blank is thrown over lower plate 18 by feed rolls and is urgeddownwardly thereon by overlying rails ll7.

When platen 11 moves generally leftwardly in FIG. 3, upon extension ofcylinder 112., a leading side edge of the blank will engage a stationarystop means or plate 16a while the platen continues to move under theplate. Simultaneously therewith, an opposite and trailing side edge ofthe blank initially enters opening 2t), defined by a rearward straightedge of plate 118 and an adjacent forward and tapered edge of plate 119.Continued leftward movement of the platen permits the blank to fullymove through the opening and to fall through a large, horizontallydisposed opening (not shown) formed through the stationary table of thedelivery station and onto conveyor 7.

The integrated drive system for the machine is synchronized to permitthe blank to fall onto the conveyor precisely, to have its trailing sideedge engaged by a pusher plate 21 secured to the conveyor. The equallyspaced plates are positioned in close linear alignment to maintainsubstantially high operating speeds during the continuous gluing andstitching operations performed at station 2. it is, of course, desirableto reduce the wasted stitch between the adjacent sack blanks to thelowest possible length.

Since it is further desirable to maintain the blanks as close togetheras possible on conveyor 7, the sack blanks must be fed downwardly ontothe continuously moving conveyor belt at exactly the right moment. Suchcoordination is readily achieved by the synchronized movements ofconveyors and 7, rollers it) and platen 11. In addition, the deliverystation is constructed to prevent the inadvertent feeding of two sackblanks simultaneously onto plate 118 and conveyor 7.

In particular, should conveyor belt 4} and rollers it feed a trailingblank into the delivery station while the platen is reciprocating tofeed a leading blank through opening 20, the trailing blank would atleast partially fall onto plate 19. The leading side edge of thetrailing blank would normally engage stop plate 11b to prevent it frominterfering with the sequential feeding of the leading blank throughopening 2i). Therefore, the feeding of a blank to conveyor 7 can only beaccomplished when the platen is in its fully retracted, Fit}. 2condition of operation wherein plate 118 is positioned to receive suchblank.

if so desired, an intermittently actuated stop mechanism (not fullyshown) could be positioned in the delivery station and forwardly ofrolls MP to prevent the inadvertent feeding of a trailing blanktherethrough until a leading blank has been fed to conveyor '7. The stopmechanism could comprise a movable arm or gate 21a synchronized with themovements of platen ill: and belt 7. In particular, such an arm or gatewould move into a blocking position in front of the gap formed betweenrolls 10 until the leading blank has been fed to conveyor 7 and platenis returned to its FIG. 2 position.

The operations performed at stations l and 2 are preferably run at thesame, synchronized speed, as dictated by the speeds of belts 4 and '7.Such synchronization may be accomplished, for example, by means of apulse counter (not shown) operatively associated with belt 4 to countthe number of sack blanks passing thereby during a predetermined timeinterval. The number counted can then be compared with a referonce valuedependent on the linear speed of conveyor belt 7 for automaticadjustment of the speed of belt 4. Alternatively, the measured value ofthe feed speed of belt 4 can be used for regulating the speed of belt 7and thus, also the number of lateral movements of platen 11 per apredetermined time interval.

What is claimed is:

1. An apparatus for feeding blanks comprising first conveyor means formoving a plurality of blanks in a first direction,

second conveyor means disposed vertically below said first conveyormeans for moving said blanks in a second direction transverse to saidfirst direction, delivery means, including a platen mounted forreciprocal movements in said second direction, for receiving said blanksfrom said first conveyor means and for continuously delivering saidblanks to said second conveyor means, feed roll means rotatably mountedbetween said first conveyor means and said delivery means for receivinga blank from said first conveyor means and for impelling said blank intosaid delivery means, over said platen, and guide means disposedvertically above said platen for urging said blank downwardly onto saidplaten.

2. The apparatus of claim 1 wherein said guide means comprises at leastone stationary rail converging downwardly toward said platen from saidfeed roll means.

3. The apparatus of claim ll wherein said platen comprises a pair ofplates having adjacent edges thereof spaced vertically apart to define adown-feed opening therebetween extending in said first direction andvertically disposed above said second conveyor means.

4. The apparatus of claim 3 wherein said delivery means furthercomprises stationary stop means extending in said first direction andpositioned vertically above said platen to permit said platen to movethereunder so that when said platen moves under said stop means aleading side edge of a blank resting on one of said plates will engagesaid stop means to permit an opposite side edge of said blank to entersaid down-feed opening.

5. The apparatus of claim ll further comprising actuating meansoperatively connected to said platen for continuously reciprocating saidplaten in said second direction.

6. The apparatus of claim 5 wherein said actuating means comprises anextensible and retractable fluid actuator mounted on a stationary frameof said delivery means, a bellcrank pivotally attached at a first endthereof to a rod end of said actuator and pivotally mounted on saidframe and lost-motion means connecting a second end of said bellcrank tosaid platen.

7. The apparatus of claim 1 further comprising tube forming meanspositioned adjacent to said first conveyor means for receiving andforming a continuous web of material into a tube and for cutting saidtube into blanks and an end closure forming means positioned adjacent tosaid second conveyor means for forming an end closure on each of saidblanks.

8. The invention of claim 1 further comprising stop means positionedbetween said first conveyor means and said feed roll means forselectively moving into a blocking position in front of said feed rollmeans to prevent the feeding of a blank to said feed roll means fromsaid first conveyor means.

9. in a blank feeding station, a horizontally disposed platenreciprocally mounted in said station for movement in a linear direction,said platen comprising first and second plates defining verticallyspaced apart edges defining a down-feed opening therebetween, disposedperpendicular relative to said linear direction, adapted to receive andguide a flattened blank therethrough.

10. A method for continuously feeding blanks comprising the steps ofmoving a plurality of blanks on a first conveyor in a first direction,

placing each blank sequentially on a platen, and

moving said platen in a second direction transverse to said firstdirection while simultaneously removing said blank from said platen,said removing step including the step of engaging an edge of said blankwith a stationary stop member to hold said blank while said platen movesthereunder.

11. The method of claim it]? wherein said removing step includes thestep of inserting said blank through an opening formed in said platenand permitting said blank to fall therebelow.

12. The method of claim W further comprising the step depositing saidblank onto a second conveyor after removal thereof from said platen andmoving said second conveyor in said second direction.

13. The method ofclaim 110 wherein said placing step includes the stepof impelling said blank in said first direction and simultaneouslyguiding said blank downwardly onto said platen.

14. The invention of claim lib further comprising the steps of firstlyforming a continuous web of material into a tube and cutting said tubeinto a plurality of blanks, while said tube moves in said firstdirection, and lastly forming an end closure on each blank.

15. An apparatus for feeding blanks comprising first conveyor means formoving a plurality of blanks in a first direction,

second conveyor means disposed vertically below said first conveyormeans for moving said blanks in a second direction transverse to saidfirst direction and delivery means, including a platen mounted forreciprocal movements in said second directiomfor receiving said blanksfrom said first conveyor means and for continuously delivering saidblanks to said second conveyor means, said platen comprising a pair ofplates having adjacent edges thereof spaced vertically apart to define adown-feed opening therebetween extending in said first direction andvertically disposed above said second conveyor means, said deliverymeans further comprising stationary stop means extending in said firstdirection and positioned vertically above said platen to permit saidplaten to move thereunder so that when said platen moves under said stopmeans a leading side edge of a blank resting on one of said plates willengage said stop means to permit an opposite side edge of said blank toenter said down-feed opening.

116. An apparatus for feeding blanks comprising first conveyor means formoving a plurality of blanks in a first direction,

second conveyor means disposed vertically below said first conveyormeans for moving said blanks in a second direction transverse to saidfirst direction delivery means, including a platen mounted forreciprocal movements in said second direction, for re cciving saidblanks from said first conveyor means and for continuously deliveringsaid blanks to said second conveyor means and actuating means,operatively connected to said platen for continuously reciprocating saidplaten in said second direction, comprising an extensible andretractable fluid actuator mounted on a stationary frame of saiddelivery means, a bellcrank pivotally attached at a first end thereof toa rod end of said actuator and pivotally mounted on said frame andlost-motion means connecting a second end of said bellcrank to saidplaten.

17. A method for continuously feeding blanks comprising the steps ofmoving a plurality of blanks on a first conveyor in a first direction,

placing each blank sequentially on a platen, and

moving said platen in a second direction transverse to said firstdirection while simultaneously removing said blank from said platen,said removing step including the step of inserting said blank through anopening formed in said platen and permitting said blank to falltherebelow.

18. A method for continuously feeding blanks comprising the steps ofmoving a plurality of blanks on a first conveyor in a first direction,

placing each blank sequentially on a platen, including the step ofimpelling said blank in said first direction and simultaneously guidingsaid blank downwardly onto said platen, and

moving said platen in a second direction transverse to said firstdirection while simultaneously removing said blank from said platen.

2 i t "i i

1. An apparatus for feeding blanks comprising first conveyor means formoving a plurality of blanks in a first direction, second conveyor meansdisposed vertically below said first conveyor means for moving saidblanks in a second direction transverse to said first direction,delivery means, including a platen mounted for reciprocal movements insaid second direction, for receiving said blanks from said firstconveyor means and for continuously delivering said blanks to saidsecond conveyor means, feed roll means rotatably mounted between saidfirst conveyor means and said delivery means for receiving a blank fromsaid first conveyor means and for impelling said bLank into saiddelivery means, over said platen, and guide means disposed verticallyabove said platen for urging said blank downwardly onto said platen. 2.The apparatus of claim 1 wherein said guide means comprises at least onestationary rail converging downwardly toward said platen from said feedroll means.
 3. The apparatus of claim 1 wherein said platen comprises apair of plates having adjacent edges thereof spaced vertically apart todefine a down-feed opening therebetween extending in said firstdirection and vertically disposed above said second conveyor means. 4.The apparatus of claim 3 wherein said delivery means further comprisesstationary stop means extending in said first direction and positionedvertically above said platen to permit said platen to move thereunder sothat when said platen moves under said stop means a leading side edge ofa blank resting on one of said plates will engage said stop means topermit an opposite side edge of said blank to enter said down-feedopening.
 5. The apparatus of claim 1 further comprising actuating meansoperatively connected to said platen for continuously reciprocating saidplaten in said second direction.
 6. The apparatus of claim 5 whereinsaid actuating means comprises an extensible and retractable fluidactuator mounted on a stationary frame of said delivery means, abellcrank pivotally attached at a first end thereof to a rod end of saidactuator and pivotally mounted on said frame and lost-motion meansconnecting a second end of said bellcrank to said platen.
 7. Theapparatus of claim 1 further comprising tube forming means positionedadjacent to said first conveyor means for receiving and forming acontinuous web of material into a tube and for cutting said tube intoblanks and an end closure forming means positioned adjacent to saidsecond conveyor means for forming an end closure on each of said blanks.8. The invention of claim 1 further comprising stop means positionedbetween said first conveyor means and said feed roll means forselectively moving into a blocking position in front of said feed rollmeans to prevent the feeding of a blank to said feed roll means fromsaid first conveyor means.
 9. In a blank feeding station, a horizontallydisposed platen reciprocally mounted in said station for movement in alinear direction, said platen comprising first and second platesdefining vertically spaced apart edges defining a down-feed openingtherebetween, disposed perpendicular relative to said linear direction,adapted to receive and guide a flattened blank therethrough.
 10. Amethod for continuously feeding blanks comprising the steps of moving aplurality of blanks on a first conveyor in a first direction, placingeach blank sequentially on a platen, and moving said platen in a seconddirection transverse to said first direction while simultaneouslyremoving said blank from said platen, said removing step including thestep of engaging an edge of said blank with a stationary stop member tohold said blank while said platen moves thereunder.
 11. The method ofclaim 10 wherein said removing step includes the step of inserting saidblank through an opening formed in said platen and permitting said blankto fall therebelow.
 12. The method of claim 10 further comprising thestep depositing said blank onto a second conveyor after removal thereoffrom said platen and moving said second conveyor in said seconddirection.
 13. The method of claim 10 wherein said placing step includesthe step of impelling said blank in said first direction andsimultaneously guiding said blank downwardly onto said platen.
 14. Theinvention of claim 10 further comprising the steps of firstly forming acontinuous web of material into a tube and cutting said tube into aplurality of blanks, while said tube moves in said first direction, andlastly forming an end closure on each blank.
 15. An apparatus forfeeding blanks comprising first conveyor means for moving a plUrality ofblanks in a first direction, second conveyor means disposed verticallybelow said first conveyor means for moving said blanks in a seconddirection transverse to said first direction and delivery means,including a platen mounted for reciprocal movements in said seconddirection, for receiving said blanks from said first conveyor means andfor continuously delivering said blanks to said second conveyor means,said platen comprising a pair of plates having adjacent edges thereofspaced vertically apart to define a down-feed opening therebetweenextending in said first direction and vertically disposed above saidsecond conveyor means, said delivery means further comprising stationarystop means extending in said first direction and positioned verticallyabove said platen to permit said platen to move thereunder so that whensaid platen moves under said stop means a leading side edge of a blankresting on one of said plates will engage said stop means to permit anopposite side edge of said blank to enter said down-feed opening.
 16. Anapparatus for feeding blanks comprising first conveyor means for movinga plurality of blanks in a first direction, second conveyor meansdisposed vertically below said first conveyor means for moving saidblanks in a second direction transverse to said first direction deliverymeans, including a platen mounted for reciprocal movements in saidsecond direction, for receiving said blanks from said first conveyormeans and for continuously delivering said blanks to said secondconveyor means and actuating means, operatively connected to said platenfor continuously reciprocating said platen in said second direction,comprising an extensible and retractable fluid actuator mounted on astationary frame of said delivery means, a bellcrank pivotally attachedat a first end thereof to a rod end of said actuator and pivotallymounted on said frame and lost-motion means connecting a second end ofsaid bellcrank to said platen.
 17. A method for continuously feedingblanks comprising the steps of moving a plurality of blanks on a firstconveyor in a first direction, placing each blank sequentially on aplaten, and moving said platen in a second direction transverse to saidfirst direction while simultaneously removing said blank from saidplaten, said removing step including the step of inserting said blankthrough an opening formed in said platen and permitting said blank tofall therebelow.
 18. A method for continuously feeding blanks comprisingthe steps of moving a plurality of blanks on a first conveyor in a firstdirection, placing each blank sequentially on a platen, including thestep of impelling said blank in said first direction and simultaneouslyguiding said blank downwardly onto said platen, and moving said platenin a second direction transverse to said first direction whilesimultaneously removing said blank from said platen.